This is the story of two young men who grow up in Boston to become policemen. They confront each other, one as a spy for a criminal, the other as an undercover agent infiltrating the criminal organization.
The undercover cop is Billy Costigan. His father’s family were hardened criminals, already the stuff of legend around their parts. His mother, now dying, was shunned by her family, for marrying beneath them. His father, long dead, was a nobody, but a thoroughly honest man. The boy decides to be a cop. The cops have two objections. His criminal family & his great SAT scores. If he does not want to end up a criminal like his father’s family, he could just take up wealth & status from his mother’s family. He apparently is uninterested in imitating his father. Whichever side of his family he chooses, he is choosing the good. Legal or otherwise.
Costigan rejects the good. Why? We see his great contempt for both sides of his family, but we only see him take action against the criminals. He wants to do justice because they are unjust. He wants to prove that he is not like them – he is humiliated to be reminded of the connection. The possibility that that connection will haunt him for the rest of his life takes him close to despair.
The police cannot trust him, because of his family. They cannot allow him to become a notable policeman: What would people say, given his family? But his family connections make him ideal for undercover work. He has both the experience & the reputation required. The police want him to become a criminal, not just to pretend to be a criminal. He needs to do evil in order to later prove that the criminal has done evil.
The consequences are dire: He gradually loses his mind & ends up desperately in need of pills to fight off panic attacks. The intimacy with an evil man removes from Costigan any hope that he could gain a reputation as a policeman. Everything he wanted to be, or to appear to be, is taken from him. All this is required in the name of justice, which he places above the good. Doing evil to the evil really requires doing evil, he learns. If he hates criminals, he will have to live with that hatred.
Retribution asks: Who are the enemies of the city? Who will fight them? This assumes that some few will never obey the laws. They pursue their own good against the laws & against the spirit of the laws. They arouse the desires & the fears that lead to tyranny. They corrupt the meaning of political freedom.
The remake of Infernal Affairs, which earned Scorsese his long-awaited Oscar